Track for snowmobile or the like

ABSTRACT

The disclosure herein describes an endless flexible track for a snowmobile or the like which comprises at least two laterally spaced and longitudinally extending strips of elastomeric material, a plurality of equidistantly spaced reinforcing members incorporated in the strips and extending transversely thereof, and roller means rotatably mounted on the reinforcing members and defining between the strips at least one row of sprocket-teethreceiving openings. This type of construction considerably diminishes wear due to friction between the sprocket teeth and the flexible track looped around the driving and idler sprockets.

' United States Patent 1191 Chaumont TRACK FOR SNOWMOBILE OR THE LIKE[75] Inventor: Guy-NoelChaumont,

Tring-Jonction, Quebec, Canada [73] Assignee: Dayco Corporation, Dayton,Ohio [22] Filed: Mar. 2, 1971 [21] Appl. No.: 120,159

[52] US. Cl. 305/38, 305/52 [51] Int. Cl 362d 55/24 [58] Field of Search305/35 EB, 38, 52, 305/ 18 [56] References Cited UNITED STATES PATENTS3,477,767 11/1969 McNeil 305/38 3,612,625 10/1971 Huber 305/38 2,012,9589/1935 Colby 305/38 3,508,796 4/1970 Paulson 305/38 3,509,955 5/1970Lichfield 305/38 3,658,392 4/1972 Perreault 305/24 3,690,741 9/1972Pierson 304/38 i II i i "1* 1 3 [451 Aug. 28, 1973 FOREIGN PATENTS ORAPPLICATIONS 462,126 7/1928 Germany 305/38 574,161 3/1924 France 305/35EB 28,979 1925 France 305/35 EB Primary Examiner-Richard .1. JohnsonAttorney-Reuben Wolk [57] ABSTRACT The disclosure herein describes anendless flexible track for a snowmobile or the like which comprisesatleast two laterally spaced and longitudinally extending strips ofelastomeric material, a plurality of equidistantly spaced reinforcingmembers incorporated in the strips and extending transversely thereof,and roller means rotatably mounted on the reinforcing members anddefining between the strips at least one row of sprocket-teeth-receivingopenings. This type of construction considerably diminishes wear due tofriction between the sprocket teeth and the flexible track looped aroundthe driving and idler sprockets.

7 Claims, 13 Drawing Figures Pawmd Au 28, 1973 3,754,798

3 Sheets-Sheet l 4/ wri -1, 0, 0,11 i' INVENTOR Guy-Noel CHAUMO/VTPatented Aug. 28, 1973 3 Sheets-Sheet I,

Ywt 3 NA E m q. Zul/ 4V2 INVENTOR Guy-Noel CHAUMONT BY ZWflfim? ,9 7'

Patented Aug. 28, 1973 3,754,798

3 Sheets-Sheet 15 FIG. 77

FIG. 73

INVENTOR I Guy-Noel CHAUMONT TRACK FOR SNOWMOBILE OR THE LIKE The.present invention relates to tracks for selfpropelled vehicles; moreparticularly, this invention pertains to an improvement in themanufacture of an endless flexible track of the type normally used fordriving snowmobiles or the like.

At present, the track used on this type of vehicle is commonly made of athin and elastomeric material with a generally flat inner surface and acorrugated outer surface; the endless track is looped around a frontdriving sprocket and a rear idler sprocket, the teeth of which arereceived in a row of holes longitudinally extending through the track.Some vehicles are provided with a pair of driving sprockets and a pairof idler sprockets, in which case the track has two spaced rows ofsprocket-teeth-receiving holes. In order to increase the rigidity of thetrack in its lateral extent to withstand the driving force of thesprocket teeth, lateral reinforcing rods are embedded, or partiallyembedded, in the elastomeric track. To prevent wear due to frictionbetween the sprocket teeth and the elastomeric material, a wearing metalclip is usually crimped around the rubber material between adjacentholes; in some other cases, as, described in Canadian Patent No. 833,436issued Feb. 3, 1970 to Guy-Noel Chaumont, metal clips are embedded inthe rubber material with front and rear portions providing wearsurfaces. In each case, wear is inevitable due to the frictional contactbetween the sprocket teeth and the metal clips; furthermore, andespecially in the fonner case, the metal clips, inevitably, are subjectto corrosion and are often dislodged from the track.

It is an object of this invention to provide a track for snowmobiles orthe like wherein the friction normally present when the track engagesthe front and rear sprocket teeth, is considerably diminished, therebyincreasing the life and efficiency of the track.

The present invention relates to an endless driving track for use in asnowmobile or the like, comprising in its broadest aspect, at least twolaterally spaced and longitudinally extending strips of flexiblematerial having inner and outer peripheral surfaces, a plurality ofequidistantly spaced reinforcing members incorporated in the strips andextending transversely thereof, and roller means rotatably mounted onthe reinforcing members and defining with the spaced strips at least onerow of sprocket-teeth-receiving openings extending longitudinally of thetrack.

Having thus generally described the nature of the invention, particularreference will be made to the accompanying drawings illustratingpreferred embodiments thereof and in which:

FIG. I is a fragmentary plan view of one form of a track constructedaccording to the present invention;

FIG. 2 is an exploded view showing the layup of a track similar to thatshown in FIG. 1;

FIG. 3 is a transverse cross-sectional view taken along lines 33 of FIG.1;

FIG. 4 is a transverse cross-sectional view taken along lines 44 of FIG.1;

FIG. 5 is a longitudinal cross-sectional view taken along lines 55 ofFIG. 1;

FIG. 6 is a longitudinal cross-sectional view taken along lines 66 ofFIG. 1;

FIG. 11 is a schematic side view of the present track looped around anidler sprocket and a driving sprocket;

FIG. 12 is a fragmentary top plan view of another form of a track madein accordance with the present invention; and

FIG. 13 is a fragmentary top plan view of another form of a track madein accordance with the present invention.

Referring to FIG. 1 of the drawings, a portion of an endless flexibletrack is shown and is generally denoted by the numeral 14. The track hasan outer groundcontacting surface 16 provided with a tread, theconfiguration of which may adopt various patterns of corrugation. Thetrack has also an inner peripheral surface 18 (see FIG. 3) which isgenerally flat to receive the wheels of the snowmobile suspensionassembly (not shown). The track illustrated in FIGQI displays threelaterally spaced rows of aligned sprocket-teethreceiving openings 20, 21and 22 which extend longitudinally of the track and divide the track infour longitudinally extending strips 24, 25, 26 and 27. The track ismade of elastomeric material; FIG. 2 shows a typical layup for formingsuch a track. An outer layer 30 is of rubber followed by a layerv ofwoven nylon 32, a second layer of rubber 34, a layer of longitudinallyextending steel cables 36 and a second layer of woven nylon 38; thecentral portion of the track further includes another layer of rubber4,0. A reinforcing member 42 extends transversely of the track. Thelongitudinal edge portions of the track further includes, underneath theopposite ends of the reinforcing member 42, a third layer of rubber 44followed by a third layer of woven nylon 46 and a fourth layer of rubber48. The particular construction of a track similar to the one shown inFIG. 2 is the subject of a co-pending application filed by applicantconcurrently herewith. It is therefore wished to have it understood thatthe present invention, as hereinafter described, is not limited to theparticular construction of the track shown in FIG. 2, nor is it limitedto any particular tread design for the outer surface of the track.

In FIGS. 2-6, the reinforcing member 42 shown is a flat rigid bar ofrectangular cross-section and with two midportions 50 and 52 ofi'setrelative to three raised portions 54, 56 and S8. The offset prevents anylateral movement of the reinforcing member once molded in v theelastomeric material. However, the shape of the reinforcing member 42may be modified in various ways, for instance, the reinforcing membermay be completely or partially embedded in the elastomeric material; itis therefore wished to have it understood that, again, the presentinvention is not limited to the particular shape of the reinforcingmember shown in the drawings.

The essential feature of the present invention consists in mountingroller means on each reinforcing member in the one or more rows ofopenings of the track, thereby considerably reducing wear due tofriction between the sprocket teeth and the track. These roller meansare cylindrically shaped members and are made of nylon, polycarbonate,polyurethane or other like suitable material.

In the construction of the track illustrated in FIGS. 3-6, roller means60, 61 and 62 are mounted to revolve on and about the raised portions54, 56 and 58 of the reinforcing member 42 in the rows of openings 20,21 and 22, respectively. Because the reinforcing member 42 isrectangular in cross-section, each of the roller means 60, 61 and 62, inthis particular embodiment, consists of a tubular member 64 which isfitted for rotation over a pair of coupling members 66 received atoposite ends of the tubular member and fixed onto the reinforcing bar42. Each coupling member 66 is cylindrically shaped and has a centralopening 68 of a shape corresponding to that of the cross-section of thereinforcing member; the circular outer wall of each coupling memberincludes a flanged portion 70 of larger diameter than that of theremaining portion 72. The inner wall of tubular member 64 is shaped tocorrespondingly receive the flanged portion 70 and the smaller portion72 of each coupling member 66. The material of the coupling members maybe the same as that of the tubular members or may be any other suitablewear-resistant material. The edges 74 and 76 of each coupling memberextend beyond the associated peripheral side surfaces 77 of the tubularmember to distance the revolving member 77 from the elastomericmaterial.

As mentioned above, the outer surface 16 has a specific tread designmolded therein. This design is defined, in the present track, by aseries of transverse ribs 78 and longitudinal ribs 80 which provide thenecessary traction in the longitudinal and transverse direction. Toprevent wear and friction due to contact between the periphery of eachroller with the ground surface, it is preferable to leave a clearancespace d between the apexes of the longitudinal ribs 80 and the plane Atangent to the outer peripheral surface of the rollers. The lowertangent plane B of the outer surface of the rollers may extend adistance d below the plane of the inner surface 18 of the track; suchpreferred construction will especially find advantageous applications inslide rail suspensions, such as schematically represented in FIG. 11where the rollers act as support for the slide rails.

FIGS. 9 and illustrate another embodiment of the invention in the casewhere the reinforcing member is a rod 82 circular in cross-section; itis therefore evident that the presence of coupling members, similar tothose described above, are no longer required. The roller means are, inthis case, revolving cylinders 84 with a circular central opening 86axially extending therethrough to receive rod 82.

In the operation of the present track, reference is made to theschematic view of FIG. 11 wherein the track is looped around a drivingsprocket 88 fixed onto a front driving axle 90 and around an idlersprocket 92 mounted on a rear axle 94; it can be seen that when rollers96 are received between the teeth of the driving and idler sprockets,friction between the engaging surfaces of the respective members willconsiderably be diminished due to the rollers revolving about thereinforcing members when engaged and rotating with the sprocket teeth.

FIGS. 12 and 13 illustrate that the present invention is also applicableto a track 98 having a pair of spaced rows of sprocket-teeth-receivingopenings 100 and 102 or to a track 99 having a single row of openings104.

The invention has been described above to show that it may beincorporated in various types of tracks and with various shapes ofreinforcing members; it is therefore wished to have it understood thatthe present invention is not limited in interpretation and in scope except by the terms of the following claims.

What I claimed is:

1. An endless driving track for use in a snowmobile or the likecomprising at least two laterally spaced and longitudinally extendingstrips of elastomeric material having inner and outer peripheralsurfaces; a plurality of equidistantly spaced reinforcing membersincorporated in said strips and extending transversely thereof; androller means rotatably mounted on the reinforcing members and definingwith said spaced strips at least one row of sprocket-teeth-receivingopenings extending longitudinally of the track; each of said reinforcingmembers comprising a rigid bar of non-circular crosssection, said rollermeans including a tubular member having a circular opening and a pair ofcoupling members received in the opposite ends of said opening andfixedly mounted on said reinforcing member, said tubular member beingrotatable relative to said coupling members, each of said couplingmembers having an axial opening extending therethrough for receivingsaid reinforcing member, the configuration of said axial opening of saidcoupling member corresponding to the cross-sectional shape of saidreinforcing member.

2. An endless track as defined in claim 1, wherein said cross-sectionalshape of said reinforcing member is rectangular.

3. An endless track as defined in claim 1, wherein peripheral sidesurfaces of said coupling members extend beyond related peripheral sidesurface of said tubular member.

4. An endless track as defined in claim 1, comprising two laterallyspaced rows of sprocket-teeth-receiving openings and threelongitudinally extending strips of elastomeric material.

5. An endless track as defined in claim 1, comprising three laterallyspaced rows of sprocket-teeth-receiving openings and four longitudinallyextending strips of elastomeric material.

6. An endless track as defined in claim 1, wherein said outer surfacehas a tread design defined by longitudinal and transverse ribs, saidlongitudinal ribs extending at least along said row of openings, theapexes of said longitudinal ribs adjacent said row of openings extendingbeyond the tangent plane of said roller means on the side of the outersurface of the track.

7. An endless track as defined in claim 6, wherein said inner surface isgenerally flat and wherein the tangent plane of the roller means on theside of said inner surface of the track extends beyond the plane of saidinner surface.

1. An endless driving track for use in a snowmobile or the likecomprisIng at least two laterally spaced and longitudinally extendingstrips of elastomeric material having inner and outer peripheralsurfaces; a plurality of equidistantly spaced reinforcing membersincorporated in said strips and extending transversely thereof; androller means rotatably mounted on the reinforcing members and definingwith said spaced strips at least one row of sprocket-teeth-receivingopenings extending longitudinally of the track; each of said reinforcingmembers comprising a rigid bar of non-circular cross-section, saidroller means including a tubular member having a circular opening and apair of coupling members received in the opposite ends of said openingand fixedly mounted on said reinforcing member, said tubular memberbeing rotatable relative to said coupling members, each of said couplingmembers having an axial opening extending therethrough for receivingsaid reinforcing member, the configuration of said axial opening of saidcoupling member corresponding to the cross-sectional shape of saidreinforcing member.
 2. An endless track as defined in claim 1, whereinsaid cross-sectional shape of said reinforcing member is rectangular. 3.An endless track as defined in claim 1, wherein peripheral side surfacesof said coupling members extend beyond related peripheral side surfaceof said tubular member.
 4. An endless track as defined in claim 1,comprising two laterally spaced rows of sprocket-teeth-receivingopenings and three longitudinally extending strips of elastomericmaterial.
 5. An endless track as defined in claim 1, comprising threelaterally spaced rows of sprocket-teeth-receiving openings and fourlongitudinally extending strips of elastomeric material.
 6. An endlesstrack as defined in claim 1, wherein said outer surface has a treaddesign defined by longitudinal and transverse ribs, said longitudinalribs extending at least along said row of openings, the apexes of saidlongitudinal ribs adjacent said row of openings extending beyond thetangent plane of said roller means on the side of the outer surface ofthe track.
 7. An endless track as defined in claim 6, wherein said innersurface is generally flat and wherein the tangent plane of the rollermeans on the side of said inner surface of the track extends beyond theplane of said inner surface.